2012-09-14  Richard Guenther  <rguenther@suse.de>

	* tree-vrp.c (register_new_assert_for): Simplify for backward
	walk.
	(find_assert_locations_1): Walk the basic-block backwards,
	properly add/prune from live.  Use live for asserts derived
	from stmts.

From-SVN: r191293